b 1. FIELD OF THE INVENTION
This invention pertains to the repair of internal combustion engine coolant radiators and more particularly concerns fixturing and hand tools for recoring of such radiators.
2. DESCRIPTION OF THE PRIOR ART
In the course of repairing such radiators, recoring is often found to be necessary in which the tube-and-fin "core" of the radiator is removed from the top and bottom tanks. Conventional radiator construction includes a tank joined to the core in which a header receives the core tubes and forms the bottom of the tank when the tank is mounted within the header. The most common radiator construction currently employed includes a brass tank which is soldered to the header. In recoring the radiator, the soldered joint is loosened for removal of the tank, and upon recoring, the tank is placed into the header and the solder connection rerun.
Recently there has developed a trend towards replacement of the brass tank with a plastic tank which is mechanically joined to the header. The plastic tank is positioned against a gasket in order to seal the plastic tank to the header. The plastic tank is secured in position with a series of tabs formed integrally with the header, which are bent down onto the tank flange to retain the plastic tank compressed against the gasket.
Radiator repair shops have for the most part relied on impromptu fixturing for conducting these operations.
Reassembly of the brass tank to the header has often involved difficulties due to deformation of the tank bottom or slight irregularities in the header recess receiving the tank lip, such that a degree of pressure is necessary in order to get the tank to properly seat. In addition, there sometimes exists excessive clearance between the tank lip and the header tank recess, which in turn results in a weaker solder joint. The handling of the disassembly and reassembly of the tank and radiator core and header is relatively difficult and slows completion of the recoring.
Plastic tank designs have presented their own peculiar problems in recoring, particularly in crimping and decrimping of the tabs while properly ensuring a seal of the plastic tank bottom against the gasket and the header.
The crimped tabs are difficult to loosen because they are often jammed tightly into the tank flange, with minimal clearance between the plastic tank side wall and the tab end, making it difficult to obtain insertion of a tool for decrimping. The compression of the tank flange against the gasket further aggravates the problem due to the tightness with which the tabs are consequently forced against the tank flange.
Obtaining a proper seal between the header and the plastic tank is also troublesome since, if the header recess receiving the gasket is deformed, leakage will occur. Such deforming can be inflicted by the decrimping operation or the subsequent crimping operation due to pressure exerted by hand tools on the outer edge of the header.
In addition, the entire tank crimping and decrimping operations are relatively time consuming, resulting in a high cost of labor to recore a radiator.
Plastic tanks are, in the United States, only now beginning to be found in numbers but, ultimately, may account for the bulk of radiator repairs. In the interim, both types of radiators will necessarily need to be accommodated. Since fixturing therefor is relatively costly, it represents a sizeable capital investment for businesses having the limited financial resources of a typical radiator repair shop, and it is important that any fixturing intended for that application be adaptable to both types of tanks.
Frequently, radiator shops have accommodated plastic tanks by using decrimping and crimping tools which have either been conventional hand tools, such as vise grips pressed into service for this purpose, or have been specially designed pneumatic tools. In the case of conventional hand tools, these do not efficiently perform the crimping and decrimping operations and, therefore, require excessive labor. The pneumatic tools, on the other hand, are relatively expensive and are difficult to control, often applying excessive force to the tab due to a lack of "feel" associated with their manipulation.
A solution to the dilemma faced by radiator shop operators is provided by my U.S. Pat. No. 4,462,146 which provides a radiator recoring fixture as well as tools therefor for both conventional brass and plastic tank radiators. In that patent, a fixture is disclosed having a pair of clamping gates each of which is provided with parallel side rails that are adjustably spaced to receive a radiator header. The fixture further includes a pair of hold down elements, which, in cooperation with a clamping bar, press the header onto the side rails by a pneumatically operated cylinder. When a conventional brass tank radiator is being recored, it is placed between a first set of side rails in a position so that its header sits atop the side rails. When a plastic tank radiator is being recored, it is placed between a second set of side rails. Each of the side rails of the second set of side rails has a slot running along its inside, facing corners; the header is placed into the slot formed in the top on each of these side rails. To secure crimping and decrimping of the tabs on the header, a crimping tool and a decrimping tool are respectively provided which cooperate with the second set of side rails.
The decrimping tool consists of a bar section with a handle at one end extending from one side thereof. The bar section is formed with a slot for receiving a pivotable trigger rod. The opposite end of the bar section is formed with an oppositely extending anchor block, which has a throughbore for receiving a spring loaded plunger. The spring loaded plunger has one end engaged with the trigger rod so that it is caused to be extended forwardly of the anchor block. The anchor block is also formed with an inclined mounting surface to which is mounted a downwardly extending hook finger. A knob is also mounted atop the anchor block. In use, the decrimping tool plunger is positioned against one of the rails, the hook finger being in registry with the tab to be decrimped, such that the finger is inserted behind the tab and at the tank side. The hook finger is held down in this position by pressure being applied on the knob. Squeezing of the trigger rod and extension of the plunger produces outward pressure between the finger and the tab, resulting in a pivoting movement of the decrimping tool which enables ready bending upwardly of each of the tabs.
The crimping tool consists of a handle frame to which is joined an angled clevis. The angled clevis, in turn, is pivotally mounted to a swing bar which is affixed to a finger lever. The finger lever includes a rearwardly extending lever rod and forwardly extending finger. A channel block is mounted across the ends of the clevis and is structured to interlock with the slot at the bottom of the rail. In use, the tool is positioned with a crimping finger in registry with a tab to be crimped, the lever rod is then manipulated downwardly while the handle is pulled upwardly to rotate the tool with respect to the rail, causing neat rolling over of the tab into the crimped position.
While my U.S. Pat. No. 4,462,146 has solved many of the problems described above, the crimping and decrimping tools described therein are somewhat awkward to use and require too much attention by the repairman to ensure proper operation. Further, the aforesaid crimping and decrimping tools require both hands of the repairman during operation, which tends to slow down how quickly the operations can be performed as compared to the rapidity of operation if only one hand was necessary therefor.
Accordingly, there remains in the art the need to provide a crimping and decrimping tool, each of which cooperates with a set of side rails, so that only one-handed operation is required in a manner that is easily, smoothly and quickly executed by the repairman.